Apparatus for making concrete culvert pipes



I Feb. 18, 1958 H. H. SCHMIDGALL APPARATUS FOR MAKING CONCRETE CULVERT PIPES Filed July 21, 1954 l w L( a I m 9 9 71/ V I. J n a J 5 Z a 7 a 1 A a 6 HR n u. m G F HLQM ,IHJ; L 3

W WW GNI ENTOR.

UnitedStates My invention relates 'tdiniprovements in apparatus for making concrete culvert pipes.

The objects of myinv'ention'are to provide an 'improved means for forming the tongue on one/end of concrete culvert pipes; to provide means which will facilitate more rapid manufacture of such pipes andl avoid delay for curing the concrete after a mold has beerrfilled; to provide improved'rrieans to'insure accuratelyfitted tight junctions between'successive pipes and r'or'gua'rdin against any misalignment or crookedness of the parts at the joints; to protect the tongues and heads of the pipes against injury while the molds are being removed.

I attain these objects by the means shown in the accompanying drawings, in which:

Figure 1 shows a side elevation of my molds with an upwardly sloping projection of the concrete at the top of the pipe;

Figure 2 shows a perspective view of the upper end of forms 1 and 11 with the header 9 and lever 8 in locked position;

Figure 3 is a sectional detail of the upper part of forms 1 and 11 with the header 9 and lever 8, on the line 3-3 of Figure 2;

Figure 4 is a quarter-sectional detail of the header 9.

Similar numerals refer to similar parts throughout the several views.

My apparatus includes a base 2 with an upwardly projecting ring formed thereon to form the recess which receives the tongue of the next succeeding section of a culvert.

Resting upon this base is a cylindrical form 1 which extends upwardly to the desired height of a section of culvert pipe 10. One edge of the pipe is provided with a circular tongue 10.1 which will extend into the recess in the adjoining end of the next succeeding pipe section when assembled in a culvert.

An inner cylindrical form 11 is mounted upon the base plate 2 and extends upwardly a little farther than the upper end of the form 1. A circular header 9 is provided with its outer circumference adjoining the inside circumference of the form 1, and with its inner circumference adjacent to the outer circumference of the inner form 11.

This header includes a sloping mid-portion with an outwardly extending flange united to its lower edge and an inwardly extending flange united to the upper edge thereof of the size and shape desired to form the male and female members of the joint or junction of two culvert pipes, and with lugs or hooks 9.1 united to the header 9 and extending outwardly a trifle less than the thickness of the pipe wall so that when the pipe is finished, the form 1 can be withdrawn without disturbing the header.

Each lug forms a hook upon which a chain 8.1 may be attached having a downwardly extending bar or link 9.2 united thereto. The lower end of each bar 9.2 is mounted with a pivot 7 upon the lever 8. The lever 8 has a longer arm which forms a handle and an angular shorter arm pivoted at 8.2 to an arm 6 of a brackets which is united to the form 1. Whenthe-leverS is in upright position, the chains 8.1 may be hooked or linked tothe threesides of the header.

lugs -9.1;and when the levers 8 are lowered they; will exerta strong 'downward'p'ull upon the header 9 at 7 This will insure uniform movement of the header anduniform pressure upon the inclined upper edge of the concrete pipe and guard against any tilting or misalignment.

A plurality of metal rings may be secured in the molds between the inner and outer forms to reenforce the pipe.

The concrete is made by a moist or' semi-wet mixtureof cement, -sand, gravel, crushed 'rock or other available matter, but not wet enough to pour or run, but moist enough to be firmly adherent when compressed. The

mixture-may be conducted to the open upper end of the mold-made by the forms 1 and 11, by a spiral conveyor 'or othersuitable meansas desired and may b dropped into the mold soformed.

While the mixture is being placed in the mold, the mold and its contents are subjected to rapid vibration by chain ;3 and vibrator 3.1 or byanyof the means commonly known for that purpose.

This vibration continues while the mold is being filled. The upper edge of the pipe is then beveled from its contact with the upper edge of form 1 up to its contact at or close to the upper edge of form 11. The uniform pressure of the header all around the top of the pipe will add to the compaction of the concrete which stabilizes it against displacement when and as the forms 1 and 11 are removed.

When the header is applied and forced downwardly, if there is any excess of concrete, it will be forced outwardly by the header over the upper edge of the form 1. The vibration will be kept up during this movement of the header thereby insuring greater compaction.

Immediately after the header has been forced downwardly to or slightly below the level of the top of the form 1, the inner form 11 is drawn upwardly, being contracted for that purpose if necessary. By that time the concrete is firm enough to remain in place. Means for contracting the inner form 11 may be of any of the forms in use for that purpose and are preferably applied before moving it so as to insure free movement thereof without disturbing the concrete, or the header. Likewise the form 1 may have means to expand it enough to free it from the concrete pipe.

' After the inner form 11 has been withdrawn, the outer form may be lifted by hoisting means of any suitable form, but with the header remaining in place upon the top of the pipe until the form 1 has been entirely withdrawn.

After the form 1 has been withdrawn, the header 9 may be removed and the pipe removed from the base.

The base and forms 1 and 11 may then be reassembled and additional culvert pipes constructed in the same way.

Experience has shown that with this apparatus the time required to make and perfect a large concrete culvert pipe may be reduced to 7 /2 minutes and my apparatus and method therefore afford exceptionally effective means for large scale production of concrete cuivert pipes as described.

Various modifications may be made in the form, material and proportion of the parts without departing from the spirit of my invention as expressed in the claims, and I do not limit my claims to the precise forms shown in the drawings.

I claim:

1. Apparatus of the class described, comprising: an upright cylindrical outer form and an upright cylindrical inner form concentrically within said outer form to afford an annular space for receiving a concrete mix, said forms having bottom edge portions proximate to each other and further having top edge portions proximate to each other; means supporting the forms via their bottom edge portions and including a bottom header closing the bottom of the annular space; a top header in, the form of form and engaging the top header at correspondingly uniformly angularly spaced portions thereof and operative to exert downward forces on said top header for forcibly lowering said top header to a final position Within said annular space and thereby to increase the compaction of the mix adjacent to said top edge portions, each force-exerting means including an anchor projecting outwardly from the exterior of the outer form at a level below the top edge portions, a first link attached to said anchor and extending upwardly therefrom, a lever fulcrumed on the first link and extending radially outwardly, and a second link attached to the top header and connected formly angularly about the exterior wall of the outer to the lever in radially outwardly spaced relation to the lever fulcrum so that downward force applied to the lever acts through the second link and reacts against the first link and anchor to force the header downwardly.

2. The invention defined in claim 1, in which: the links and lever in each force-exerting means are substantially identical and the anchors are at a common level whereby the force-exerting means have uniform motion and thereby limit the final position of the top header to a radial plane normal to the axis of the forms.

References Cited in the file of this patent UNITED STATES PATENTS 11,440 Pierce Aug. 1, 1854 45,229 Dayton Nov. 29, 1864 384,295 Stockwell June 12, 1888 846,279 Bannon Mar. 5, 1907 952,578 Reber et a1. Mar. 22, 1910 1,036,867 Mack Aug. 27, 1912 1,162,924 Homing Dec. 7, 1915 1,407,569 Pedersen Feb. 21, 1922 1,423,284 Weaver July 18, 1922 1,789,818 Hyden et a1 Jan. 20, 1931 1,954,904 Walter Apr. 17, 1934 2,559,296 Hansen July 3, 1951 

